More than 27,000 fans are expected to flock to the gig in Myrtle Park and Gareth's mum told a local paper:
"It will be fantastic. He'll be really pleased to play there to say thank you to his fans - I'm sure it will be just unreal."
Crowds are expected to be even bigger than last year when Steps appeared.
Tickets are on sale priced £5 on 01274 435000 or from St George's Hall in Bradford.